The prior art includes U.S. Pat. Nos. 7,0303,602; 6,680,616; 6,160,697; Serway, Physics for Scientists and Engineers, Saunders College Pub. 1996; and IEEE Standard C57.13-1993 Standard Requirements for Instrument Transformers. The disclosures of these references are hereby incorporated herein by reference. The above listing is not intended to be a representation that a complete search of all relevant art has been made, or that no more pertinent art than that listed exists, or that the listed art is material to patentability. Nor should any such representation be inferred.